One of moving picture encoding and/or decoding systems wherein a spatial resolution between an input picture and an output picture is varied is a layer encoding/decoding system investigated in the ISO-IEC/JTC1/SC29/WG11. In the layer encoding/decoding system, basically on the encoder side, an input image of a low resolution is encoded in a lower layer to form a bit stream, and a decoded picture of the bit stream of the lower layer is converted by up conversion and used for encoding of an other input picture of an upper layer having a high resolution. On the other hand, on the decoder side, the decoded picture of the lower layer is converted by up conversion and used for decoding of a bit stream of the upper layer.
A detailed example of such layer encoding/decoding systems is disclosed in Proposal for Test Model 2, ISO-IEC/JTC1/SC29/WG11, revision 2, pp. 101-108, Oct. 19, 1992.
The layer encoding/decoding system, however, has a subject to be solved in that, since it is constructed so as to cope only with the case wherein the input is an interlace picture, it cannot cope with another case wherein the input is a non-interlace image.